1. Field of the Invention
The present invention relates to a sorting apparatus for sorting copy papers discharged from an image forming apparatus of a copying machine, a printing machine and so on, the sorting apparatus detecting exchange of a manuscript on the basic of discharge time interval of the copy papers.
2. Description of the Related Art
Hitherto, in an off-line type sorting apparatus, to which signals of the copying machine are not supplied, the copying machine copies and discharges the copy papers to the sorting apparatus at time intervals as shown in FIG. 1.
That is, FIG. 1 shows such case that 5 pieces of copy papers are sorted for a first manuscript and the first manuscript is exchanged, and further 5 pieces of copy papers are sorted for a second manuscript.
In FIG. 1, T.sub.1 indicates the discharge time interval of the sorted copy papers for the first manuscript. T.sub.2 indicates the exchange time interval of the first manuscript to the second manuscript. T.sub.3 indicates the discharge time interval of the sorted copy papers for the secnd manuscript. Then as shown in FIG. 1, the time interval T.sub.2 is designed to be larger than the time intervals T.sub.1, T.sub.3 so that the sorting apparatus can detect the manuscript exchange.
Thus the sorting apparatus detects the number of the sorting copy papers for one manuscript (hereinafter abbreviated as sorting number) on the basis of time interval T.sub.2 and memorizes the sorting number and further sorts for subsequent (second, third, . . . ) manuscript by utilizing the sorting number. However, the sorting apparatus is designed in a manner that even after the sorting number is detected and memorized by utilizing the first manuscript, and even when the sorting is executed for the second manuscript and after, the manuscript exchange time interval T.sub.2 is designed to be larger than the time intervals T.sub.1, T.sub.3 by the copying machine, and thereby the subsequent manuscript exchange is detected by the sorting apparatus by both the sorting number and the time interval T.sub.2.
The reason why the manuscript exchange time interval T.sub.2 is designed to be larger than the time intervals T.sub.1, T.sub.3 for the subsequent manuscript is discussed below.
On occasion, the copying machine happens to copy papers of over the memorized number for the same one manuscript with regard to the subsequent manuscript. In such a case, the sorting apparatus should consider the case as an sorting-over-error and should discharge the superfluous copy papers into a lowest bin tray. This is the above-mentioned reason.
In other words, with regard to the sorting of the subsequent manuscript, when the manuscript exchange time interval T.sub.2 is not larger than the time intervals T.sub.1, T.sub.3, the sorting apparatus cannot detect the sorting-over-error.
However, in such conventional sorting apparatuses, total copying operation time of the copying machine is long, since the manuscript exchange time intervals T.sub.2 of the subsequent manuscript is larger than the time intervals T.sub.1, T.sub.3.